app.py

##########################################
# Step 0: Import required libraries
##########################################
import streamlit as st  # For building the web application interface
from transformers import (  # For text classification, text-to-speech, and text generation
    pipeline,
    SpeechT5Processor,
    SpeechT5ForTextToSpeech,
    SpeechT5HifiGan,
    AutoModelForCausalLM,
    AutoTokenizer
)
from datasets import load_dataset  # To load speaker embeddings dataset
import torch  # For tensor operations
import soundfile as sf  # For saving audio as .wav files
import sentencepiece  # Required by SpeechT5Processor for tokenization

##########################################
# Streamlit application title and input
##########################################
# Display a deep blue title in a large, visually appealing font
st.markdown(
    "<h1 style='text-align: center; color: #00008B; font-size: 50px;'>🚀 Just Comment</h1>",
    unsafe_allow_html=True
)  # Set deep blue title

# Display a gentle, warm subtitle below the title
st.markdown(
    "<h3 style='text-align: center; color: #5D6D7E; font-style: italic;'>I'm listening to you, my friend～</h3>",
    unsafe_allow_html=True
)  # Set a friendly subtitle

# Add a text area for user input with placeholder and tooltip
text = st.text_area(
    "Enter your comment",
    placeholder="Type something here...",
    height=100,
    help="Write a comment you would like us to respond to!"  # Provide tooltip
)  # Create text input field

##########################################
# Step 1: Sentiment Analysis Function
##########################################
def analyze_dominant_emotion(user_review):
    """
    Analyze the dominant emotion in the user's comment using a fine-tuned text classification model.
    """
    emotion_classifier = pipeline(
        "text-classification",
        model="Thea231/jhartmann_emotion_finetuning",
        return_all_scores=True
    )  # Load the sentiment classification model
    emotion_results = emotion_classifier(user_review)[0]  # Get sentiment scores for the input text
    dominant_emotion = max(emotion_results, key=lambda x: x['score'])  # Identify the emotion with highest score
    return dominant_emotion  # Return the dominant emotion (as a dict with label and score)

##########################################
# Step 2: Response Generation Functions
##########################################
def prompt_gen(user_review):
    """
    Generate the text generation prompt based on the user's comment and detected emotion.
    """
    # Get dominant emotion for the input
    dominant_emotion = analyze_dominant_emotion(user_review)  # Analyze user's comment
    # Define response templates for 7 emotions
    emotion_strategies = {
        "anger": {
            "prompt": (
                "Customer complaint: '{review}'\n\n"
                "As a customer service representative, craft a professional response that:\n"
                "- Begins with a sincere apology and acknowledgment.\n"
                "- Clearly explains a solution process with concrete steps.\n"
                "- Offers appropriate compensation or redemption.\n"
                "- Keeps a humble and solution-focused tone (1-3 sentences).\n\n"
                "Response:"
            )
        },
        "disgust": {
            "prompt": (
                "Customer quality concern: '{review}'\n\n"
                "As a customer service representative, craft a response that:\n"
                "- Immediately acknowledges the product issue.\n"
                "- Explains measures taken in quality control.\n"
                "- Provides clear return/replacement instructions.\n"
                "- Offers a goodwill gesture (1-3 sentences).\n\n"
                "Response:"
            )
        },
        "fear": {
            "prompt": (
                "Customer safety concern: '{review}'\n\n"
                "As a customer service representative, craft a reassuring response that:\n"
                "- Directly addresses the safety worries.\n"
                "- References relevant certifications or standards.\n"
                "- Offers a dedicated support contact.\n"
                "- Provides a satisfaction guarantee (1-3 sentences).\n\n"
                "Response:"
            )
        },
        "joy": {
            "prompt": (
                "Customer review: '{review}'\n\n"
                "As a customer service representative, craft a concise response that:\n"
                "- Thanks the customer for their feedback.\n"
                "- Acknowledges both positive and constructive points.\n"
                "- Invites them to explore loyalty or referral programs (1-3 sentences).\n\n"
                "Response:"
            )
        },
        "neutral": {
            "prompt": (
                "Customer feedback: '{review}'\n\n"
                "As a customer service representative, craft a balanced response that:\n"
                "- Provides additional relevant product information.\n"
                "- Highlights key service features.\n"
                "- Politely requests more detailed feedback.\n"
                "- Maintains a professional tone (1-3 sentences).\n\n"
                "Response:"
            )
        },
        "sadness": {
            "prompt": (
                "Customer disappointment: '{review}'\n\n"
                "As a customer service representative, craft an empathetic response that:\n"
                "- Shows genuine understanding of the issue.\n"
                "- Proposes a personalized recovery solution.\n"
                "- Offers extended support options.\n"
                "- Maintains a positive outlook (1-3 sentences).\n\n"
                "Response:"
            )
        },
        "surprise": {
            "prompt": (
                "Customer enthusiastic feedback: '{review}'\n\n"
                "As a customer service representative, craft a response that:\n"
                "- Matches the customer's positive energy.\n"
                "- Highlights unexpected product benefits.\n"
                "- Invites the customer to join community events or programs.\n"
                "- Maintains the brand's voice (1-3 sentences).\n\n"
                "Response:"
            )
        }
    }  # Dictionary mapping each emotion to a prompt template
    # Get the template for the detected emotion, default to 'neutral' if not found
    template = emotion_strategies.get(dominant_emotion["label"].lower(), emotion_strategies["neutral"])["prompt"]
    prompt = template.format(review=user_review)  # Insert the user review into the template
    print(f"Generated prompt: {prompt}")  # Debug print using f-string
    return prompt  # Return the generated prompt

def response_gen(user_review):
    """
    Generate a response using text generation based on the user's comment.
    """
    prompt = prompt_gen(user_review)  # Get the generated prompt using the detected emotion template
    # Load the tokenizer and language model for text generation
    tokenizer = AutoTokenizer.from_pretrained("Qwen/Qwen1.5-0.5B")  # Load tokenizer for text generation
    model = AutoModelForCausalLM.from_pretrained("Qwen/Qwen1.5-0.5B")  # Load causal language model for generation
    inputs = tokenizer(prompt, return_tensors="pt")  # Tokenize the prompt
    outputs = model.generate(
        **inputs,
        max_new_tokens=100,  # Allow up to 100 new tokens for the answer
        min_length=30,  # Ensure a minimum length for the generated response
        no_repeat_ngram_size=2,  # Avoid repeated phrases
        temperature=0.7  # Use a moderate temperature for creativity
    )  # Generate response from the model
    input_length = inputs.input_ids.shape[1]  # Determine length of the input prompt
    response = tokenizer.decode(outputs[0][input_length:], skip_special_tokens=True)  # Extract only generated answer text
    print(f"Generated response: {response}")  # Debug print using f-string
    return response  # Return the generated response

##########################################
# Step 3: Text-to-Speech Conversion Function
##########################################
def sound_gen(response):
    """
    Convert the generated response to speech and embed an auto-playing audio player.
    """
    # Load SpeechT5 processor, TTS model, and vocoder
    processor = SpeechT5Processor.from_pretrained("microsoft/speecht5_tts")  # Load TTS processor
    model = SpeechT5ForTextToSpeech.from_pretrained("microsoft/speecht5_tts")  # Load TTS model
    vocoder = SpeechT5HifiGan.from_pretrained("microsoft/speecht5_hifigan")  # Load vocoder
    # Process the full generated response text for TTS
    inputs = processor(text=response, return_tensors="pt")  # Convert text to model input tensors
    # Use dummy speaker embeddings with shape (1,768) to avoid dimension mismatch
    speaker_embeddings = torch.zeros(1, 768, dtype=torch.float32)  # Create dummy speaker embedding
    spectrogram = model.generate_speech(inputs["input_ids"], speaker_embeddings)  # Generate speech spectrogram
    with torch.no_grad():
        speech = vocoder(spectrogram)  # Convert spectrogram to waveform
    # Save the audio as a .wav file with 16kHz sampling rate
    sf.write("customer_service_response.wav", speech.numpy(), samplerate=16000)  # Write the waveform to file
    st.audio("customer_service_response.wav", start_time=0)  # Embed an auto-playing audio widget

##########################################
# Main Function
##########################################
def main():
    """
    Main function to orchestrate text generation and text-to-speech conversion.
    It displays only the generated response and plays its audio.
    """
    if text:  # Check if the user has entered a comment
        response = response_gen(text)  # Generate a response using text generation based on emotion
        st.markdown(
            f"<p style='color:#3498DB; font-size:20px;'>{response}</p>",
            unsafe_allow_html=True
        )  # Display the generated response in styled format
        sound_gen(response)  # Convert the generated response to speech and embed the audio player
        print(f"Final generated response: {response}")  # Debug print using f-string

# Execute the main function when the script is run
if __name__ == "__main__":
    main()  # Call the main function